SeanR

Don't know if this is covered on any instructions that you were given. But GROUND the radiator to the car in some way. Otherwise it won't last that long and it will start to leak.

Joe F

I don't think it's deliberate, and it might not be a problem on some 928's. But I agree, the C & R aluminum radiator I got has a fit problem with the small hose on top in my '88 S4. It bumps into the hood frame when the hood is closed.

I think if they used a 90 degree fitting instead of a straight one it would solve the problem. My hood doesn't close as nicely on the drivers side as it once did, but I cannot bring myself to grind an opening into the hood frame to clear that fitting.

YMMV

davek9

You asked about coolant type and if you should use water wetter?

I use the Dexcool 5 year (came in silver 1 gal jug) and bought it 50/50 pre mixed and added one bottle of the water wetter first and then just filled it up.

Ran the car w/o the cap on, keeping an eye on the overflow tank, and every time it got sucked down I turned off the engine and refilled it half way (heater on full heat), finally it stopped.
I put the cap on let it idle for a bit and checked for leaks and took it for a ride, topped off until it settled down in about two more hot / cold cycles.

It never ran cooler (the new thermostat and block ‘O” ring that goes in that cross over between the heads also helped.
I am about to do it again (the refill process) as I have my rad out now, doing a tbwp job.

I think, no I am sure, this is kinda like your choice of oil and many will debate my selection (like paying for the water in the 50/50 mix). So be it... begin

Bill Ball

My understanding is it is best to mix coolant 50/50 for corrosion protection regardless of the need for anti-freeze protection.

BC

20% is the minimum for corrosion protection if you have no concern for freezing, and realisitically, 20% goes down to 0 degrees F (IIRC)

Bill Ball

Brett: You know of course how the t-stat on the 928 operates the opposite of most american cars and how easy it can be for people to install it incorrectly with the o-ring seal on the wrong side. What about having them replace the seal that is under the T-stat? That's rather unique too.

Bill Ball

Maybe I swallowed some bad information. I don't care about freeze protection that much either, but I have been using 50% mix for anticorrosion

Bret928

I don't know how accurate the 20% is but I'm with Brendan in that the you can use less than 50% antifreeze.

perrys4

My understanding is plain old water runs cooler than anti freeze but it gives some lubrication to the pump.

RyanPerrella

water transfers heat more efficently then does water + whatever. So Ron you are correct. But you need something to work as an anti corrosive agent and to lubricate the system.

I think Brendan is good with 20%, although I would just go 25-30% myself.

Another thing that hasnt been mentioned and i am suprised is that you should really use distilled water. Buy 2 gallons of it and your good to go.

I read 5 gallons for the mixing coolant here, keep in mind system only holds 2 gallons IIRC.

Good luck

And for the Formula 1 fun fact of the day: F1 cars run only 4 liters of coolant. (just over a gallon) This is pretty impresive to me if youve ever seen the size of their rad's ( and bear in mind there are 2+ per car) i think you would agree.

Bret928

Interesting the manual says the system holds ~16.9 qts (or 4.225 Gallons). Where’s the rest of that 5 gals go? The overflow/recovery tank?

While nothing is mentioned for a 20% mix the manual seems to promote Brendan’s assertion that we don’t need more than that if we don’t have to worry about dropping below freezing:

Manual quote:
40% mix (good for -13deg F): Antifreeze 6.8qts + water 10.1qts = 16.9qts.

checkmate1996

Trust me it holds 5 gallons. I used a five gallon plastic gas jug to capture the water. It was almost full, but it was all in the radiator, overflow and in the block.

SteveG

Picky, but in the materials category, you will need a new zip tie for the lower hose. I assume the early mods also secure the hose to the shroud.

BC

http://www.redlineoil.com/whitePaper/17.pdf

Bret928

Good link Brendan,

Well the bad news is they had some slacker taking up space in one of the stalls in the auto shop so everything's on hold til tomorrow afternoon. Talking to the teacher he was pretty upset that the student didn't finish what he was doing or at least pull his pile of crap out of the lift stall.

I'll update everyone tomorrow evening.